Anomalous-dispersion phase-matched second-harmonic generation

We have demonstrated anomalous-dispersion phase-matched second-harmonic generation, using electric-field-induced second-harmonic generation in a liquid solution of Foron Brilliant Blue S-R (FBB). This dye has a sharp absorption maximum near 620 nm and a deep absorption minimum near 450 nm. The microscopic hyperpolarizability (beta) of FBB was measured at 1.58 and 0.954 microm and was found to be 163 x 10(-30) and -118 x 10(-30) cm(5)/esu, respectively. The change in sign of beta and the observation that beta(0), a frequency-independent measure of hyperpolarizability, is the same at both frequencies demonstrate the validity of the two-state model of the second-order hyperpolarizability.